Molecular beam epitaxy of three-dimensionally thick Dirac semimetal Cd3As2 films

Rapid progress of quantum transport study in topological Dirac semimetal, including observations of quantum Hall effect in two-dimensional (2D) Cd3As2 samples, has uncovered even more interesting quantum transport properties in high-quality and three-dimensional (3D) samples. However, such 3D Cd3As2 films with low carrier density and high electron mobility have been hardly obtained. Here, we report the growth and characterization of 3D thick Cd3As2 films adopting molecular beam epitaxy. The highest electron mobility (μ = 3 × 104 cm2/Vs) among the reported film samples has been achieved at a low carrier density (n = 5 × 1016 cm−3). In the magnetotransport measurement, Hall plateau-like structures are commonly observed despite the 3D thick films (t = 120 nm). On the other hand, the field angle dependence of the plateau-like structures and corresponding Shubunikov-de Haas oscillations rather shows a 3D feature, suggesting the appearance of an unconventional magnetic orbit, also distinct from the one described by the semiclassical Weyl-orbit equation.